Conversion of carbonaceous materials into a fuel gas



S p 1952 J. c. KALBACH 2,609,283

CONVERSION OF CARBONACEOUS MATERIALS INTO A FUEL GAS Filed Aug. 9, 1947 TA? f LIGHT 0/1..

RECOVER) 74R, ETC.

FUEL 6A5 AER-4 T/IVG LIGHT O/L.

INVENTOR.

Jo NC. Kn 5 OH iay'v'aemams Patented Sept. 2, 1952 CONVERSION OF CARBONACEOUS MATERIALS INTO A FUEL GAS John C. Kalbach, New York, N. IL, assignor to Hydrocarbon Research, Inc., New-York N. Y., a-corporation of New Jersey Application August 9, 1947, Serial No. 767,793

This invention relates to the carbonization and gasification of solid carbonaceous materials such as coal, oil shale, lignite, and the like to produce fuel gases of relatively high heating values.

The prior art relating to the production of fuel gases from coal is replete with diverse processes. However, all of such processes fall into two general classes, namely, the cheaper processes productive of fuel gases of relatively low calorific value such aspro'ducer gas, and the more complicated processes productive of fuel gases of higher calorific value but too expensive for practical application. One of the latest proposals in this art involves the processing of the coal of separate carbonization andgasification steps, the coal being carbonized by hot coke from the subsequent gasification step, wherein a part of the coke is oxidized to bring the remainder of the mass to a sufficiently high temperature for the recycle. (However, this process has the disadvantage of requiring the recycling of a large stream of hot coke or other heat carrier to provide the heat for the coal carbonization, and the further disadvantage of the carbonizing and gasifying temperature being dependent variables, controllable only to a limited extent and materially influenced by the ratio of recycle coke to fresh coal or a compromisebetween desired conditions in the two steps.

In improving over the prior art, the present invention has as a major object the provision of anovel carbonization and gasification process wherein the heat required for carbonization is generated in situ by hydrogenation of the material within the carbonization zone under predetermined pressure and temperature conditions, no cycling or recycling of hot coke or other heat carrier being required.

Another object of the invention isthe provision of a novel process wherein the carbonization of the material is accomplished with simultaneous hydrogenation, the gaseous products of the carbonization and the hydrogenation forming a fuel gas of a relatively high calorific value.

A further object of the invention is to provide a novel process wherein the carbonization ofthe material is effected along with hydrogenation, the products of the overall operation being processed in a manner to supply substantially all the hydrogen requirements for the process.

Otherv objects and advantages of the invention willibe apparent from the following description and'claims taken in connection with the accompanying drawing wherein: 1

Fig. 1 is a diagrammatic showing of a process 4 Claims. (01. 48-197) illustrating a preferred application of the invention.

Fig. 2 illustrates a modified process embodying the invention.

In its broader aspect, the presentinvention is directed to the carbonization and gasification of a solid carbonaceous material in particles of relatively fine sizes, capable ofbeing fluidized, by contacting the fresh material in. the fluidized phase with hydrogen'or a hydrogen-containing gas to effect the hydrogenation of material in the carbonization zone with the, generation of heat, the removal of the volatiles and the formation of coke; the subsequent oxidation or gasification of the coke in the fluidized phase; and the selection and combination of constituents of the gaseous products from both operations'to produce a final fuel gasof high calorific content. More specifically, the invention contemplates the supplying of the heat requirements for the carbonization by the exothermic hydrogenation; and the production of the hydrogen requirements in connection with the preparation or separation of the oxygen for the gasification step, the costs of the gases being thus brought down to practical limits.

Referring to Fig. l, the apparatus shown therein in diagrammatic'fashion includes a feed hopper II, a combined carbonization-hydrogenation reactor I2, a tar and light oil recovery unit l3, a gasification reactor 14, and a combined oxygen and hydrogen separation unit [5. Suitable connections and auxiliary apparatus are described later in connection, with the manner of operation or the apparatus. T

In carrying out the process, coal, in finely divided form and capableof being fluidized by a gaseous medium is fed from hopper 'll into a line l6 carrying hydrogen or a hydrogen-rich gas at a suflicient velocity to carry the coal intoi reactor l2 and maintain the coal particles'therein in a fluidized, ebullient mass having the appearance of a boiling liquid. The. coal particles are preferably less than 46-60 mesh in size, 40-50 per cent thereof being200 mesh or smaller, the fiuidizing medium. being introduced at' a rate such that its rate-of flow in the. reactor is in the order of about 0.5-3.0 feet per second.

The hydrogen and the contents'ofreactor 12 are caused to react 'exothermically; the fiuidizing action ensuring excellent contactbetween the'gas and the particles. "At"thesame time,.distillation takes place wherein the volatile material is driven from the coal and under the prevailing reaction conditions there is little or no tendency for the for the distillation. Therefore, excess coke is transferred to the gasification chamber Id. The rates of feed to the reactor 12 are controlled so that the temperature therein is in the range of 1000 to 1500" F., the pressure eing in t e range of 300 to 750 pounds per square inch gauge.

At lower temperatures, the methane is relatively low.

production A cyclone separator I I, connected to the reactor [2 by lines l8 and I9, serves to separate entrained solids from the reaction gases, and to return them to the reactor, the gaseous prod ucts exiting through line 2]. The latter, including methane, hydrogen, carbon monoxide; light oil, tar and hydrogen sulfidepass through a, liquid recovery unit l3 wherein, tar, light .oil and other liquid constituentsv are separated from. the reaction gasesf The, separated gas mixture is takenofi through line24'. V

Coke is taken from adjacent the bottom of re actor l2 by line 25 and fed into a stream of an oxygen containing gas (preferably not less than 95 per cent oxygen) in line 26, usua ly supplemented with steam, The coke particles are thus transported to and fluidized in reactor 54', the steam and oxygen reacting withthecoke to form the desired gaseous mixture, Preferably the gasification reaction is conducted at a temperature in the range of 1400" to 2400" F; and a pressure in the range of atmospheric to 300 pounds per squareinch gauge. The proportion ofsteam and oxygen to the coke can. be varied in well known manner to varythej composition of the product gas. Thus, synthesis gas consisting essentially of one part of carbon monoxide to two parts of hydrogen for synthesis of hydrocarbons, oxygenated compounds or the like can be prepared, the gas being taken off through'a line 27 and passedto a synthesisreactor orstorage facili'- ties; Otherwise, the gas may'fl'ow through line 22 and mix with the gas line 24 to provide a fuel gas of desired characteristics.

The gaseousproducts may also be "conveyed through line 28 to a low temperature separation unit [5 wherein the carbon'monoxide andhydrogen are separated, the carbon monoxide leaving through line 29. The latter stream by flowing through line 29A may be mixed with the gas in line 24 to form in line 3] "a fuel gas with a heatingvalue of 500to1 55 B. t. u. per 'cubicfoot. This relatively high heating value is secured without, the necessity ofhigh temperature carburation or the use ofa Fischer-type synthesis unit. Preferably the low temperature separation unit I is of, a type wherein the steps of separating oxygen from air entering through line 32 and separating hydrogen from the product gases in line 28 are accomplished in afsingle coordinated unit, the oxygen being fed through line 33 to line 26 and the hydrogen through line 34 to'line i6. Water and carbon dioxide are removed through line 35-. If desired, the as separations can be accomplished in separate units.

Fig.2 illustrates a modiflcationof the 'inven'-' tion wherein the feed'hopper l I; acornbinedcar- 4 bonization and hydrogenation reactor 4| and a gasification reactor 42 are arranged in vertical relation, the remaining components of the system being the same as shown in Fig. 1, like reference characters being applied thereto. The coal, in a finely divided form capable of being fluidized, is fed through line- 43 into reactor 4!, the hydrogen-containing. gas being introduced at the bottom of the reactor through line 34 and reacting with the fluidized contents in the same manner as described in connection with Fig. 1. The gaseous products are removed through lines i8 and Z! and processed as already described. The coke is conducted through line 4-3 into rea'cto'r'; 2'iorgasification by its reaction with oxygen and steamcharged through line 26, the

used herein anddn gaseous products being processed as already described. This arrangement possesses the advan tage that the coal and its solid residue follow a vertical path, the flow thereof being accomplished through gravity.

n thE es ol. d z, ash is removedyat ten.- venient' joints suitable ,lines v therefor being shown; Inviewbf the relatiyely high, pressures emp oy d t: some states. nv the process. it is! to be understood that's if able. valve controlled seals will be used whereyeit necessary i accordance with wellfknowhjengineering Practice.

It will be noted herein that. it isv unnnec'e'ssja'ry y l an ity nif g lqi' like heat, carr Bi; to supply theheat for thecarbonizatibh, the heat requirements thereforwith the'prbdubtion 'of desirable gas products, being secured byjcontrolled hydrogenation within the 'carbohiza'tiqn, zone.

Additionally the carbonizirig and-taming, steps are entirely independent, there e1 g no recycle of coke or other'heat.carrerithfirbe W891i dictating any relation insect tendin-ens;t uthv as heat and pressure. J a o The retardation er the hydrogenation by tarbon monoxide in the "carbonizing step, is avoided or materially minimized by recycling the, carbohization zon'eihl ilfogen substantially free or carbon monoxide and excellent coiitr'ols. over the; various steps and the finalproductsl are obtained, those tontros bem available ts the, end that, the'degrees of c pennants and gas ification and: the characteristics of theIinal product-s can be; Widely and a'sily'varied.

, While coal has been describedhereinfby way of example as the: feed materiahit is, to be derstood that any carbonaceous rnateria-l having: vclatil-izable constituents and, leaving ajsolid. caronctnta n n r si ue-ca be. similarly pr s--- essed. 'The term; arbonaceo-us material?" as: h apnendedaclaims' isv ins tended to. define such feed materials; "she proc essing of such materials asmoil. shales. having a relatively high con'tentof: inert material is also contemplated" since; such inert material canbe:

Also, the fresh coal or like,

I claim:

1. In a process for producing fuel gas of high heating value from a solid carbonaceous material containing volatilizable constituents, the improvement which comprises simultaneously hydrogenating and carbonizing autogenously said solid carbonaceous material by continuously contacting said carbonaceous material in comminuted form in a dense phase fluidized bed with a stream of hydrogen at a pressure within the range of from about 300 to about 750 pounds per square inch gauge and at a substantially uni form temperature within the range of from about 1,000 to about 1,500 F. in a carbonization zone. continuously introducing said carbonaceous material into said carbonizatio-n zone, discharging a gaseous product comprising hydrocarbons and. unreacted hydrogen from said carbonization zone, continuously withdrawing carbon-containing residue from said carbonization zone and reacting said residue in a gasification zone with an oxygen-containing gas and steam to produce a mixture of carbon monoxide and hydrogen, separating hydrogen from said mixture, passing said hydrogen to the carbonization zone as the source of hydrogen for reaction with said solid carbonaceous material. and admixing carbon monoxide separated from said mixture with said gaseous product from the carbonization zone to REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,898,967 Schneider et al. Feb. 12, 19 33 2,094,946 Hubmann Oct. 5, 1937 FOREIGN PATENTS Number Country Date 491,453 Great Britain Sept. 2, 1938 503,158 Great Britain Apr. 3, 1939 OTHER REFERENCES Meade, Modern Gasworks Practice, 2nd edition, pp. 405-406. 

1. IN A PROCESS FOR PROODUCING FUEL GAS OF HIGH HEATING VALUE FROM A SOLID CARBONACEOUS MATERIAL CONTAINING VOLATILIZABLE CONSTITUENTS, THE IMPROVEMENT WHICH COMPRISES SIMULTANEOUSLY HYDROGENATING AND CARBONIZING AUTOGENOUSLY SAID SOLID CARBONACEOUS MATERIAL BY CONTINUOUSLY CONTACTING SAID CARBONACEOUS MATERIAL IN COMMINUTED FORM IN A DENSE PHASE FLUIDIZED BED WITH A STREAM OF HYDROGEN AT A PRESSURE WITHIN THE RANGE OF FROM ABOUT 300 TO ABOUT 750 POUNDS PER SQUARE INCH GAUGE AND AT A SUBSTANTIALLY UNIFORM TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 1,000 TO ABOUT 1,500* F. IN A CARBONIZATION ZONE, CONTINUOUSLY INTRODUCING SAID CARBONACEOUS MATERIAL INTO SAID CARBONIZATION ZONE, DISCHARGING 